Mechanisms of water and sodium retention in cirrhosis and the pathogenesis of ascites

Elevated serum HE4 levels as a novel biomarker of disease severity and hepatic fibrosis in autoimmune hepatitis

BACKGROUND

Human epididymis protein 4 (HE4) has been identified as a biomarker for renal fibrosis. This study aimed to evaluate the role of HE4 in the diagnosis and determination of disease severity and hepatic fibrosis in autoimmune hepatitis (AIH).

METHODS

Serum HE4 levels were determined via electrochemiluminescence immunoassays in 60 healthy controls and 109 AIH patients (43 without liver cirrhosis and 66 with liver cirrhosis). Liver biopsy was performed on 56 of 109 enrolled patients. We conducted a 5-year follow-up survey of 53 enrolled patients. All continuous variables were reported as median (25th-75th percentile).

RESULTS

Serum HE4 levels were significantly elevated in autoimmune hepatitis with liver cirrhosis (AIH-LC) patients compared with AIH patients and healthy controls [98.60 (74.15-139.08) vs 73.50 (59.88-82.00) vs 48.75 (43.38-52.93) pmol/L, p = 0.004]. The serum HE4 levels showed a positive correlation with the METAVIR scoring system in patients with liver biopsy (r = 0.711, p < 0.001). Serum HE4 levels were significantly elevated in Child-Pugh class C patients compared with Child-Pugh class B patients and Child-Pugh class A patients [106.50 (83.46-151.25) vs 110.00 (73.83-166.75) vs 77.03 (72.35-83.33) pmol/L, p = 0.006]. The diagnostic sensitivity and specificity of serum HE4 for evaluating liver cirrhosis were 69.7 % and 79.07 %, respectively, with a cutoff value of 82.34 pmol/L in enrolled patients. The logistic regression analysis showed that high levels of HE4 (≥82.34 pmol/L) were associated with AIH-LC (OR = 8.751, 95 % CI = 1.412-54.225, p = 0.020). The Kaplan-Meier curves demonstrated that high levels of serum HE4 (≥82.34 pmol/L) were associated with poor outcome (log-rank p = 0.037, HR = 0.372, 95 % CI = 0.146-0.946).

CONCLUSIONS

Serum HE4 levels were found to be elevated in AIH-LC patients and exhibited a strong correlation with the severity of hepatic fibrosis, thus supporting their potential clinical value as a novel biomarker of disease severity and hepatic fibrosis in AIH.

Extracellular sodium regulates fibroblast growth factor 23 (FGF23) formation

The bone-derived hormone fibroblast growth factor-23 (FGF23) has recently received much attention due to its association with chronic kidney disease and cardiovascular disease progression. Extracellular sodium concentration ([Na+]) plays a significant role in bone metabolism. Hyponatremia (lower serum [Na+]) has recently been shown to be independently associated with FGF23 levels in patients with chronic systolic heart failure. However, nothing is known about the direct impact of [Na+] on FGF23 production. Here, we show that an elevated [Na+] (+20 mM) suppressed FGF23 formation, whereas low [Na+] (-20 mM) increased FGF23 synthesis in the osteoblast-like cell lines UMR-106 and MC3T3-E1. Similar bidirectional changes in FGF23 abundance were observed when osmolality was altered by mannitol but not by urea, suggesting a role of tonicity in FGF23 formation. Moreover, these changes in FGF23 were inversely proportional to the expression of NFAT5 (nuclear factor of activated T cells-5), a transcription factor responsible for tonicity-mediated cellular adaptations. Furthermore, arginine vasopressin, which is often responsible for hyponatremia, did not affect FGF23 production. Next, we performed a comprehensive and unbiased RNA-seq analysis of UMR-106 cells exposed to low versus high [Na+], which revealed several novel genes involved in cellular adaptation to altered tonicity. Additional analysis of cells with Crisp-Cas9-mediated NFAT5 deletion indicated that NFAT5 controls numerous genes associated with FGF23 synthesis, thereby confirming its role in [Na+]-mediated FGF23 regulation. In line with these in vitro observations, we found that hyponatremia patients have higher FGF23 levels. Our results suggest that [Na+] is a critical regulator of FGF23 synthesis.

Dietary salt in liver cirrhosis: With a pinch of salt!

Patients with liver cirrhosis are advised to limit their sodium consumption to control excessive fluid accumulation. Salt is the most common form in which sodium is consumed daily. Consequently, various recommendations urge patients to limit salt intake. However, there is a lack of consistency regarding salt restriction across the guidelines. Moreover, there is conflicting evidence regarding the efficacy of salt restriction in the treatment of ascites. Numerous studies have shown that there is no difference in ascites control between patients with restriction of salt intake and those without restriction. Moreover, patients with cirrhosis may have several negative effects from consuming too little salt, although there are no recommendations on the lower limit of salt intake. Sodium is necessary to maintain the extracellular fluid volume; hence, excessive salt restriction can result in volume contraction, which could negatively impact kidney function in a cirrhotic patient. Salt restriction in cirrhotic patients can also compromise nutrient intake, which can have a negative impact on the overall outcome. There is insufficient evidence to recommend restricted salt intake for all patients with cirrhosis, including those with severe hyponatremia. The existing guidelines on salt restriction do not consider the salt sensitivity of patients; their nutritional state, volume status and sodium storage sites; and the risk of hypochloremia. This opinion article aims to critically analyze the existing literature with regard to salt recommendations for patients with liver cirrhosis and identify potential knowledge gaps that call for further research.

Compensated liver cirrhosis: Natural course and disease-modifying strategies

Compensated liver cirrhosis (CLC) is defined as cirrhosis with one or more decompensating events, such as ascites, variceal haemorrhage, or hepatic encephalopathy. Patients with CLC are largely asymptomatic with preserved hepatic function. The transition from CLC to decompensated cirrhosis occurs as a result of a complex interaction between multiple predisposing and precipitating factors. The first decompensation event in CLC patients is considered a significant turning point in the progression of cirrhosis, as it signals a drastic decline in median survival rates from 10-12 years to only 1-2 years. Furthermore, early cirrhosis has the potential to regress as liver fibrosis is a dynamic condition. With the advent of effective non-invasive tools for detecting hepatic fibrosis, more and more patients with CLC are currently being recognised. This offers clinicians a unique opportunity to properly manage such patients in order to achieve cirrhosis regression or, at the very least, prevent its progression. There are numerous emerging approaches for preventing or delaying decompensation in CLC patients. A growing body of evidence indicates that treating the underlying cause can lead to cirrhosis regression, and the use of non-selective beta-blockers can prevent decompensation by lowering portal hypertension. Additionally, addressing various cofactors (such as obesity, diabetes, dyslipidaemia, and alcoholism) and precipitating factors (such as infection, viral hepatitis, and hepatotoxic drugs) that have a detrimental impact on the natural course of cirrhosis may benefit patients with CLC. However, high-quality data must be generated through well-designed and adequately powered randomised clinical trials to validate these disease-modifying techniques for CLC patients. This article discussed the natural history of CLC, risk factors for its progression, and therapeutic approaches that could alter the trajectory of CLC evolution and improve outcomes.

Is the Development of Ascites in Alcoholic Liver Patients Influenced by Specific KIR/HLA Gene Profiles?

Decompensated cirrhosis is the most common cause of ascites due to hemodynamic and renal alteration by continuous fluid leakage from the hepatic sinusoids and splanchnic capillaries into the interstitial space. Then, fluid leakage exceeds lymphatic return, leading to progressive fluid accumulation directly into the peritoneal cavity. Alcohol consumption is one of the main risks of developing alcoholic cirrhosis (AC), but not all AC patients develop ascites. Avoiding the development of ascites is crucial, given that it deteriorates prognosis and increases the patient mortality patient. The innate immune system plays a crucial role in cirrhosis through natural killer cells, which are abundant in the liver. The aim of this study was to analyze the KIR/HLA-C genetic profile in AC patients with and without ascites to understand this pathology and find predictive clinical susceptibility biomarkers that can help to establish risks and prevent the development of ascites in AC patients. A total of 281 AC patients with and without ascites were analyzed and compared with 319 healthy controls. Genomic DNA was extracted from peripheral blood in all groups. A PCR-SSO assay was performed for KIR/HLA genotyping analysis. A total of 16 activating and inhibitor KIR genes and their corresponding known ligands, epitopes of HLA-C, and their genotypes were analyzed. According to our analysis, C1 epitopes were statistically significantly decreased in AC patients with and without ascites. When comparing AC patients with ascites and healthy controls, a significant decrease in C1 epitope frequency was also observed. A statistically significant decrease was also found when comparing the C1C2 genotype in AC patients without ascites with controls. In conclusion, the absence of KIR2DL2 and KIR3DL1 genes may be a predisposing factor for the development of ascites in AC patients. The KIR2DS2/KIR2DL2 may could be involved in grade I ascites development, and the presence of the C1+ epitope and the homozygous C2C2 genotype may be protective genetic factors against ascites development in AC patients.

Outcomes after hospitalisation with spontaneous bacterial peritonitis over a 13-year period: a retrospective cohort study

GOALS

Assess outcomes in patients with an index presentation of spontaneous bacterial peritonitis (SBP) over a 13-year period.

BACKGROUND

SBP, a bacterial infection of ascites, has a poor prognosis.

STUDY

Retrospective cohort study assessing mortality (standardised to 32 months) and prognostic factors in patients with SBP during two periods: period 1 (June 2006-November 2012) and period 2 (December 2012-May 2019).

RESULTS

The study included 178 patients who were followed up for 11.6 (29.2) months. Mortality was high, with 12-, 24- and 32-month survival being 32%, 26% and 24%, respectively. Inpatient mortality was 36% with mortality in those surviving hospitalisation being 62%. Serum creatinine at the time of SBP diagnosis was an independent predictor of mortality at 32 months [hazard ratio (HR) 1.002, P = 0.023] and inpatient mortality (HR 1.003, P = 0.035). Positive ascitic fluid culture and ascitic fluid neutrophil count were independent predictors of 32-month (HR 1.679, P = 0.008) and inpatient mortality (HR 1.0001, P = 0.005), respectively. Patients in period 2 had lower ascitic fluid albumin (5.9 ± 3.3 g/L vs. 10.8 ± 5.4 g/L, P < 0.001), higher ascitic fluid neutrophil count (815.0 cells/mm3 vs. 345.0 cells/mm3, P < 0.001) and higher rates of hepatorenal syndrome-acute kidney injury (58 vs. 35%, P = 0.002). Mortality at 32 months and mortality in those surviving hospitalisation were similar at 78 vs. 73%, P = 0.392 and 66 vs. 58%, P = 0.355, for periods 1 and 2, respectively.

CONCLUSIONS

Despite more advanced initial presentations, mortality rates have remained similar over the last 13 years. Serum creatinine at the time of SBP diagnosis is an independent predictor of mortality.

The role of transjugular intrahepatic portosystemic shunt in patients with cirrhosis and ascites: Recent evolution and open questions

In selected patients with cirrhosis and ascites, transjugular intrahepatic portosystemic shunt (TIPS) placement improves control of ascites and may reduce mortality. In this review, we summarize the current knowledge concerning the use of TIPS for the treatment of ascites in patients with cirrhosis, from pathophysiology of ascites formation to hemodynamic consequences, patient selection, and technical issues of TIPS insertion. The combination of these factors is important to guide clinical decision-making and identify the best strategy for each individual patient. There is still a need to identify the best timing for TIPS placement in the natural history of ascites (recurrent vs. refractory) as well as which type and level of renal dysfunction is acceptable when TIPS is proposed for the treatment of ascites in cirrhosis. Future studies are needed to define the optimal stent diameter according to patient characteristics and individual risk of shunt-related side effects, particularly hepatic encephalopathy and insufficient cardiac response to hemodynamic consequences of TIPS insertion.

Salt consumption and mortality risk in cirrhotic patients: results from a cohort study

Since conducting a long-term randomised clinical trial is not logical and feasible to find the optimum dosage of salt intake in patients with cirrhosis, cohort studies are the best design to assess the long-term effects of dietary salt on the survival of cirrhotic patients. This cohort study aimed to evaluate the association between dietary intake of salt and mortality risk in cirrhotic patients. The present study was designed as a cohort in three referral hospitals in Iran in 2018. One hundred and twenty-one patients aged between 20 and 70 years with established cirrhosis were recruited. Dietary intakes, demographic data and disease severity were evaluated at the baseline. Participants were followed up annually. Crude survival was greater in patients with low-to-moderate salt consumption rather than in those with high consumption, and in non-consumers [34⋅26 (95 % CI 33⋅04, 35⋅49) v. 30⋅41 (95 % CI 27⋅13, 33⋅69) v. 32⋅72 (95 % CI 30⋅63, 34⋅80), P = 0⋅028; log-rank test]. Using the Cox proportional hazard model, it was shown that the risk of mortality in the high-salt consumption category was approximately 126 % higher than that of the reference category (non-consumers) [HR value 2⋅26, (95 % CI 0⋅91, 5⋅63)], while this risk for the low-to-moderate consumption group was about 28 % lower than the reference category [HR value 0⋅72, (95 % CI 0⋅26, 1⋅99), P-trend = 0⋅04]. In conclusion, a high daily dietary intake of salt might increase the rate of mortality and moderate salt restriction (instead of elimination of salt) decreases the risk of death.

Norepinephrine innervation of the supraoptic nucleus contributes to increased copeptin and dilutional hyponatremia in male rats

Dilutional hyponatremia associated with liver cirrhosis is due to inappropriate release of arginine vasopressin (AVP). Elevated plasma AVP causes water retention resulting in a decrease in plasma osmolality. Cirrhosis, in this study caused by ligation of the common bile duct (BDL), leads to a decrease in central vascular blood volume and hypotension, stimuli for nonosmotic AVP release. The A1/A2 neurons stimulate the release of AVP from the supraoptic nucleus (SON) in response to nonosmotic stimuli. We hypothesize that the A1/A2 noradrenergic neurons support chronic release of AVP in cirrhosis leading to dilutional hyponatremia. Adult, male rats were anesthetized with 2-3% isoflurane (mixed with 95% O2/5% CO2) and injected in the SON with anti-dopamine β-hydroxylase (DBH) saporin (DSAP) or vehicle followed by either BDL or sham surgery. Plasma copeptin, osmolality, and hematocrit were measured. Brains were processed for ΔFosB, dopamine β-hydroxylase (DBH), and AVP immunohistochemistry. DSAP injection: 1) significantly reduced the number of DBH immunoreactive A1/A2 neurons (A1, P < 0.0001; A2, P = 0.0014), 2) significantly reduced the number of A1/A2 neurons immunoreactive to both DBH and ΔFosB positive neurons (A1, P = 0.0015; A2, P < 0.0001), 3) reduced the number of SON neurons immunoreactive to both AVP and ΔFosB (P < 0.0001), 4) prevented the increase in plasma copeptin observed in vehicle-injected BDL rats (P = 0.0011), and 5) normalized plasma osmolality and hematocrit (plasma osmolality, P = 0.0475; hematocrit, P = 0.0051) as compared with vehicle injection. Our data suggest that A1/A2 neurons contribute to increased plasma copeptin and hypoosmolality in male BDL rats.

Chronic exertional compartment syndrome in a patient with restrictive cardiomyopathy and portal hypertension

Chronic exertional compartment syndrome (CECS) is a condition that produces exercise-induced pain and swelling due to a transient increase in compartment pressures. It is thought to be due to muscle hypertrophy and is classically associated with young athletes under 30, overtraining, anabolic steroid use, and aberrant running biomechanics. We present a unique case of CECS in a patient without the traditional risk factors but rather diagnosed with cardiac cirrhosis and portal hypertension. This patient’s exercise-induced bilateral leg pain met the CECS criteria for leg compartment pressure testing and was attributed to fluid retention secondary to his comorbidities. His symptoms significantly improved after initiating diuretic pharmacotherapy. Based on our literature review, there is a dearth of literature associating CECS with specific chronic cardiac or hepatic conditions as well as describing its incidence in these conditions.

B-type natriuretic peptide (BNP) predicts 90-day mortality and need for paracentesis in cirrhotic patients without systolic heart failure

Fluid overload is a common complication in patients with cirrhosis. B-type natriuretic peptide (BNP) is a marker of increased blood volume, commonly used in heart failure, that has been shown to be elevated in patients with liver disease. This study examined if BNP levels can be used to determine prognosis and predict worsening of ascites in patients with cirrhosis without concomitant heart disease. A retrospective study was performed at a large urban hospital in Chicago, Illinois and included 430 patients with cirrhosis who had BNP levels ordered during their hospital stay. Patients with clinical heart failure, arrhythmias or pulmonary hypertension were excluded. The primary outcome was 90-day mortality and the secondary outcome was a requirement for therapeutic paracentesis in the 90 days following BNP results. 53 patients (12%) had BNP levels ≥ 300 pg/mL. They had significantly increased serum levels of creatinine, bilirubin, and International Normalized Ratio (INR) when compared to those with BNP < 300 pg/mL. Patients with higher BNP had significantly higher mortality rates (HR 3.49; p = 0.037) and were more likely to require therapeutic paracentesis (HR 2.26; p = 0.02) in the next 90 days. A BNP ≥ 300 pg/mL had specificity of 88.2% in predicting 90-day mortality. BNP may serve as a practical and reliable marker of underlying disease severity in patients with cirrhosis, with potential to be included in prognostication tools for assessment of end-stage liver disease.

Guidelines on the management of ascites in cirrhosis

The British Society of Gastroenterology in collaboration with British Association for the Study of the Liver has prepared this document. The aim of this guideline is to review and summarise the evidence that guides clinical diagnosis and management of ascites in patients with cirrhosis. Substantial advances have been made in this area since the publication of the last guideline in 2007. These guidelines are based on a comprehensive literature search and comprise systematic reviews in the key areas, including the diagnostic tests, diuretic use, therapeutic paracentesis, use of albumin, transjugular intrahepatic portosystemic stent shunt, spontaneous bacterial peritonitis and beta-blockers in patients with ascites. Where recent systematic reviews and meta-analysis are available, these have been updated with additional studies. In addition, the results of prospective and retrospective studies, evidence obtained from expert committee reports and, in some instances, reports from case series have been included. Where possible, judgement has been made on the quality of information used to generate the guidelines and the specific recommendations have been made according to the 'Grading of Recommendations Assessment, Development and Evaluation (GRADE)' system. These guidelines are intended to inform practising clinicians, and it is expected that these guidelines will be revised in 3 years' time.

Sex Differences in the Regulation of Vasopressin and Oxytocin Secretion in Bile Duct-Ligated Rats

INTRODUCTION

Hyponatremia due to elevated arginine vasopressin (AVP) secretion increases mortality in liver failure patients. No previous studies have addressed sex differences in hyponatremia in liver failure animal models.

OBJECTIVE

This study addressed this gap in our understanding of the potential sex differences in hyponatremia associated with increased AVP secretion.

METHODS

This study tested the role of sex in the development of hyponatremia using adult male, female, and ovariectomized (OVX) female bile duct-ligated (BDL) rats.

RESULTS

All BDL rats had significantly increased liver to body weight ratios compared to sham controls. Male BDL rats had hyponatremia with significant increases in plasma copeptin and FosB expression in supraoptic AVP neurons compared to male shams (all p < 0.05; 5-7). Female BDL rats did not become hyponatremic or demonstrate increased supraoptic AVP neuron activation and copeptin secretion compared to female shams. Plasma oxytocin was significantly higher in female BDL rats compared to female sham (p < 0.05; 6-10). This increase was not observed in male BDL rats. Ovariectomy significantly decreased plasma estradiol in sham rats compared to intact female sham (p < 0.05; 6-10). However, circulating estradiol was significantly elevated in OVX BDL rats compared to the OVX and female shams (p < 0.05; 6-10). Adrenal estradiol, testosterone, and dehydroepiandrosterone (DHEA) were measured to identify a possible source of circulating estradiol in OVX BDL rats. The OVX BDL rats had significantly increased adrenal estradiol along with significantly decreased adrenal testosterone and DHEA compared to OVX shams (all p < 0.05; 6-7). Plasma osmolality, hematocrit, copeptin, and AVP neuron activation were not significantly different between OVX BDL and OVX shams. Plasma oxytocin was significantly higher in OVX BDL rats compared to OVX sham.

CONCLUSIONS

Our results show that unlike male BDL rats, female and OVX BDL rats did not develop hyponatremia, supraoptic AVP neuron activation, or increased copeptin secretion compared to female shams. Adrenal estradiol might have compensated for the lack of ovarian estrogens in OVX BDL rats.

Brain-Derived Neurotrophic Factor and Supraoptic Vasopressin Neurons in Hyponatremia

Hyponatremia due to elevated arginine vasopressin (AVP) secretion increases mortality in liver failure patients. The mechanisms causing dysregulation of AVP secretion are unknown. Our hypothesis is that inappropriate AVP release associated with liver failure is due to increased brain-derived neurotrophic factor (BDNF) in the supraoptic nucleus (SON). BDNF diminishes GABAA inhibition in SON AVP neurons by increasing intracellular chloride through tyrosine receptor kinase B (TrkB) activation and downregulation of K+/Cl- cotransporter 2 (KCC2). This loss of inhibition could increase AVP secretion. This hypothesis was tested using shRNA against BDNF (shBDNF) in the SON in bile duct ligated (BDL) male rats. All BDL rats had significantly increased liver weight (p < 0.05; 6-9) compared to shams. BDL rats with control -shRNA injections (BDL scrambled [SCR]) developed hyponatremia with increased plasma AVP and copeptin (CPP; all p < 0.05; 6-9) compared to sham groups. This is the first study to show that phosphorylation of TrkB is significantly increased along with significant decrease in phosphorylation of KCC2 in BDL SCR rats compared to the sham rats (p < 0.05;6-8). Knockdown of BDNF in the SON of BDL rats (BDL shBDNF) significantly increased plasma osmolality and hematocrit compared to BDL SCR rats (p < 0.05; 6-9). The BDL shBDNF rats had significant (p < 0.05; 6-9) decreases in plasma AVP and CPP concentration compared to BDL SCR rats. The BDNF knockdown also significantly blocked the increase in TrkB phosphorylation and decrease in KCC2 phosphorylation (p < 0.05; 6-8). The results indicate that BDNF produced in the SON contributes to increased AVP secretion and hyponatremia during liver failure.

Midodrine and tolvaptan in patients with cirrhosis and refractory or recurrent ascites: a randomised pilot study

BACKGROUND

Splanchnic arterial vasodilatation and subsequent sodium and water retention play an important role in cirrhotic ascites. Midodrine and tolvaptan have been used separately in these patients. However, there are no reports on the use of combination of midodrine and tolvaptan in the control of ascites. The aim of this study was to evaluate the safety and efficacy of midodrine, tolvaptan and their combination in control of refractory or recurrent ascites in cirrhotics.

METHODS

Fifty cirrhotic patients with refractory or recurrent ascites were randomised to receive midodrine (n=13), tolvaptan (n=12) or both (n=13) plus standard medical therapy (SMT) or SMT alone (n=12).

RESULTS

A significant increase in urinary volume and urinary sodium at 1 and 3 months (P<.05) was observed in all groups except SMT. There was no worsening of renal or hepatic function in any group. There was deterioration of model for end-stage liver disease (MELD) in SMT. Midodrine as well as combination of midodrine and tolvaptan but not tolvaptan alone was superior to SMT in control of ascites at 3 months (P<.05). The combination therapy was also superior to midodrine in the control of ascites at 1 month. The morbidity and mortality were similar in all the groups except SMT.

CONCLUSIONS

The results of this pilot study suggest that midodrine and combination with tolvaptan better controls ascites without any renal or hepatic dysfunction. The combination therapy rapidly controls ascites as compared to midodrine or tolvaptan alone.

Albumin May Prevent the Morbidity of Paracentesis-Induced Circulatory Dysfunction in Cirrhosis and Refractory Ascites: A Pilot Study

BACKGROUND

Large-volume total paracentesis may result in paracentesis-induced circulatory dysfunction, which is associated with poor outcomes.

AIMS

To explore the short- and long-term effects of paracentesis-induced circulatory dysfunction on systemic hemodynamics, renal function and other cirrhosis-related complications in patients with refractory ascites, following subtotal large-volume paracentesis.

METHODS

Patients with cirrhosis and refractory ascites without renal dysfunction had systemic hemodynamics, renal function, and neurohormones (plasma active renin, aldosterone, norepinephrine and angiotensin II) measured pre- and 6 days post-paracentesis. Paracentesis was limited to ≤8 L with 6-8 g of albumin per liter ascites drained. Patients were followed up until transjugular intrahepatic portosystemic shunt insertion, liver transplantation, or death. Paracentesis-induced circulatory dysfunction was defined as >50 % increase in plasma active renin 6 days post-paracentesis.

RESULTS

Fifty-seven patients (mean age 59.0 ± 9.4 years) had mean 6.8 ± 1.8 L of ascites removed with 9 ± 3 g of albumin given/L of ascites drained. Patients were followed up for 715 ± 104 days. Twenty-three patients (40.4 %) developed paracentesis-induced circulatory dysfunction with unchanged serum creatinine on day six, despite worsening of hemodynamics (mean arterial pressure 90 ± 10 mmHg at baseline vs. 84 ± 8 mmHg on day six, p < 0.05). Similar hemodynamic changes were observed among patients without paracentesis-induced circulatory dysfunction. There was no significant difference in the long-term renal function or cirrhosis-related complications between the groups.

CONCLUSION

The occurrence of paracentesis-induced circulatory dysfunction, as defined by plasma active renin, may not have a significant short- and long-term impact on renal function or cirrhosis-related complications in patients with refractory ascites who undergo subtotal paracentesis with albumin infusion.

Hepatic Failure

The progression of liver disease can cause several physiologic derangements that may precipitate hepatic failure and require admission to an intensive care unit. The underlying pathology may be acute, acute-on chronic, or chronic in nature. Liver failure may manifest with a variety of clinical signs and symptoms that need prompt attention. The compromised synthetic and metabolic activity of the failing liver affects all organ systems, from neurologic to integumentary. Supportive care and specific therapies should be instituted in order to improve outcome and minimize time of recovery.

In this chapter we will discuss the definition, clinical manifestations, workup, and management of acute and chronic liver failure and the general principles of treatment of these patients. Management of liver failure secondary to certain common etiologies will also be presented. Finally, liver transplantation and alternative therapies will also be discussed.

Assessment of renal functions in patients of chronic liver disease

AIMS AND OBJECTIVES

Renal involvement in patients of chronic liver disease (CLD) is one of the dreaded complications associated with a steep rise in mortality and morbidity. Derangements in various homeostatic mechanisms in CLD leading to direct renal injury or circulatory compromise have been associated with renal impairment.

METHOD

Consecutive cirrhotic patients (n = 100) were included in the study. Structural and functional renal failure was identified and patients were classified into various renal syndromes pre renal, intra-renal and hepatorenal syndrome (HRS).

RESULTS

At the time of presentation, 37 patients had renal dysfunction. Thirty patients had pre-renal type of renal failure, six patients had intrinsic renal disease and one patient had structural renal disease. Patients with pre-renal type were further classified into volume responsive pre-renal failure and volume non responsive HRS. Five patients had features suggestive of HRS. Patients with decompensation such as portal hypertension (PHTN), jaundice, upper gastro-intestinal bleed and hepatic encephalopathy had significantly higher incidence of renal derangements as compared to their counterparts. Infection in the form of SBP and/or sepsis predisposed patients to develop renal dysfunction.

CONCLUSION

Renal impairment in patients with advanced liver disease is not an uncommon phenomenon and is more commonly associated with a more advanced disease. Presence of PHTN and various signs of decompensation increase the chances of renal derangements in these patients. In view of rising incidence of CLD and higher survival (due to better treatment options available), one should be vigilant for the renal derangements in these patients.

ANG II receptor subtype 1a gene knockdown in the subfornical organ prevents increased drinking behavior in bile duct-ligated rats

Bile duct ligation (BDL) causes congestive liver failure that initiates hemodynamic changes, resulting in dilutional hyponatremia due to increased water intake and vasopressin release. This project tested the hypothesis that angiotensin signaling at the subfornical organ (SFO) augments drinking behavior in BDL rats. A genetically modified adeno-associated virus containing short hairpin RNA (shRNA) for ANG II receptor subtype 1a (AT1aR) gene was microinjected into the SFO of rats to knock down expression. Two weeks later, BDL or sham surgery was performed. Rats were housed in metabolic chambers for measurement of fluid and food intake and urine output. The rats were euthanized 28 days after BDL surgery for analysis. A group of rats was perfused for immunohistochemistry, and a second group was used for laser-capture microdissection for analysis of SFO AT1aR gene expression. BDL rats showed increased water intake that was attenuated in rats that received SFO microinjection of AT1aR shRNA. Among BDL rats treated with scrambled (control) and AT1aR shRNA, we observed an increased number of vasopressin-positive cells in the supraoptic nucleus that colocalized with ΔFosB staining, suggesting increased vasopressin release in both groups. These results indicate that angiotensin signaling through the SFO contributes to increased water intake, but not dilutional hyponatremia, during congestive liver failure.

Tolvaptan for the treatment of liver cirrhosis oedema

No alternative therapeutic option exists if liver cirrhosis patients have insufficient response to conventional diuretics and/or experience conventional diuretic-related adverse events. In 2013, tolvaptan (7.5 mg/day), an arginine vasopressin V2 receptor antagonist, was approved in Japan for the treatment of liver cirrhosis with oedema. Short-term use of tolvaptan produced decreases in body weight, reduction in ascites volume and increases in urine volume when compared to placebo, despite the use of conventional diuretics. Additionally, approximately 60% of patients with oedema-related symptoms improved. Low-dose tolvaptan, 3.75 mg, was also efficacious. Even in patients with low serum albumin (<2.5 g/dL), decrease in body weight was greater with tolvaptan than with placebo. For future research, the efficacy and safety of lower tolvaptan doses for the treatment of liver cirrhosis patients with oedema should be confirmed in Japan. The results of this research could be used as an indicator or a guideline for physicians around the world.

Midodrine and clonidine in patients with cirrhosis and refractory or recurrent ascites: a randomized pilot study

OBJECTIVES

Splanchnic arterial vasodilatation and subsequent activation of anti-natriuretic and vasoconstrictive mechanisms have an important role in cirrhotic ascites. The aim of this study was to evaluate the effects of midodrine, clonidine, and their combination on systemic hemodynamics, renal function, and control of ascites in patients with cirrhosis and refractory or recurrent ascites.

METHODS

Sixty cirrhotic patients with refractory or recurrent ascites were prospectively studied after long-term administration of clonidine (n=15) or midodrine (n=15), or both (n=15) plus standard medical therapy (SMT), or SMT alone (n=15), in a randomized controlled trial at a tertiary center.

RESULTS

A significant increase in urinary volume, urinary sodium excretion, mean arterial pressure, and decrease in plasma renin activity (P<0.05) was noted after 1 month. There was also a significant decrease in cardiac output (P<0.05) and increase in systemic vascular resistance (P<0.05) in all groups, except clonidine. There was no change in glomerular filtration rate and model for end-stage liver disease score. Midodrine and a combination of midodrine and clonidine plus SMT were superior to SMT alone in the control of ascites (P=0.05), and there was a trend towards better control of ascites in the clonidine group (P=0.1). The mortality and frequency of various complications were similar in all groups.

CONCLUSIONS

These results suggest that midodrine, clonidine, and their combination plus SMT improves the systemic hemodynamics without any renal or hepatic dysfunction, and is superior to SMT alone for the control of ascites. However, the combination therapy was not superior to midodrine or clonidine alone.

Intracerebroventricular losartan infusion modulates angiotensin II type 1 receptor expression in the subfornical organ and drinking behaviour in bile-duct-ligated rats

Bile duct ligation (BDL) causes congestive liver failure that initiates haemodynamic changes, including peripheral vasodilatation and generalized oedema. Peripheral vasodilatation is hypothesized to activate compensatory mechanisms, including increased drinking behaviour and neurohumoral activation. This study tested the hypothesis that changes in the expression of angiotensin II type 1 receptor (AT(1)R) mRNA and protein in the lamina terminalis are associated with BDL-induced hyposmolality in the rat. All rats received either BDL or sham-ligation surgery. The rats were housed in metabolic chambers for measurement of fluid and food intake and urine output. Expression of AT(1)R in the lamina terminalis was assessed by Western blot and quantitative real-time PCR (RT-qPCR). Average baseline water intake increased significantly in BDL rats compared with sham-operated rats, and upregulation of AT(1)R protein and AT(1a)R mRNA were observed in the subfornical organ of BDL rats. Separate groups of BDL and sham-ligated rats were instrumented with minipumps filled with either losartan (2.0 μg μl(-1)) or 0.9% saline for chronic intracerebroventricular or chronic subcutaneous infusion. Chronic intracerebroventricular losartan infusion attenuated the increased drinking behaviour and prevented the increased abundance of AT(1)R protein in the subfornical organ in BDL rats. Chronic subcutaneous infusion did not affect water intake or AT(1)R abundance in the subfornical organ. The data presented here indicate a possible role of increased central AT(1)R expression in the regulation of drinking behaviour during congestive cirrhosis.

ΔFosB in the supraoptic nucleus contributes to hyponatremia in rats with cirrhosis

Bile duct ligation (BDL), a model of hepatic cirrhosis, is associated with dilutional hyponatremia and inappropriate vasopressin release. ΔFosB staining was significantly increased in vasopressin and oxytocin magnocellular neurosecretory cells in the supraoptic nucleus (SON) of BDL rats. We tested the role of SON ΔFosB in fluid retention following BDL by injecting the SON (n = 10) with 400 nl of an adeno-associated virus (AAV) vector expressing ΔJunD (a dominant negative construct for ΔFosB) plus green fluorescent protein (GFP) (AAV-GFP-ΔJunD). Controls were either noninjected or injected with an AAV vector expressing only GFP. Three weeks after BDL or sham ligation surgery, rats were individually housed in metabolism cages for 1 wk. Average daily water intake was significantly elevated in all BDL rats compared with sham ligated controls. Average daily urine output was significantly greater in AAV-GFP-ΔJunD-treated BDL rats compared with all other groups. Daily average urine sodium concentration was significantly lower in AAV-GFP-ΔJunD-treated BDL rats than the other groups, although average daily sodium excretion was not different among the groups. SON expression of ΔJunD produced a diuresis in BDL rats that may be related to decreased circulating levels of vasopressin or oxytocin. These findings support the view that ΔFosB expression in SON magnocellular secretory cells contribute to dilutional hyponatremia in BDL rats.

Region-specific changes in transient receptor potential vanilloid channel expression in the vasopressin magnocellular system in hepatic cirrhosis-induced hyponatraemia

The present study aimed to measure the expression of transient receptor potential (TRP) channels in the magnocellular neurones of the paraventricular (PVN) and supraoptic nucleus (SON) in an animal model of hepatic cirrhosis associated with inappropriate vasopressin (AVP) release. In these studies, we used chronic bile duct ligation (BDL) in the rat, which is a commonly used model of hepatic cirrhosis, associated with elevated plasma AVP. The present study tested the hypothesis that changes in TRP vanilloid (TRPV) channel expression may be related to inappropriate AVP release in BDL rats. To test our hypothesis, we utilised laser capture microdissection of AVP neurones in the PVN and SON and western blot analysis from brain punches. Laser capture microdissection and quantitative reverse transcriptase-polymerase chain reaction demonstrated elevated TRPV2 mRNA in the PVN and SON of BDL compared to sham-ligated controls. AVP transcription was also increased as determined using intron specific primers to measure heteronuclear RNA. Immunohistochemistry demonstrated increased AVP and TRPV2 positive cells in both the PVN and SON after BDL. Also, there was an increased co-expression of TRPV2 and AVP cells after BDL. However, there was no change in the colocalisation counts of TRPV2 and oxytocin in both the magnocellular regions evaluated. In the SON but not the PVN, the transcription levels of TRPV4 were also significantly increased in BDL rats. Western blot analysis of punches containing the PVN and SON revealed that TRPV2 protein content was significantly increased in these brain regions in BDL rats compared to sham rats. Our data suggest that regionally specific changes in TRPV expression in the magnocellular neurosecretory cell AVP neurones could alter their osmosensing ability.

Midodrine in patients with cirrhosis and refractory or recurrent ascites: a randomized pilot study

BACKGROUND & AIMS

Splanchnic arterial vasodilatation plays an important role in cirrhotic ascites. The aim of this study was to evaluate the effects of long term administration of midodrine on systemic hemodynamics, renal function, and control of ascites in patients with cirrhosis and refractory or recurrent ascites.

METHODS

Forty cirrhotic patients with refractory or recurrent ascites were prospectively studied after long term administration of midodrine plus standard medical therapy (n=20) or standard medical therapy alone (n=20) in a randomized controlled trial at a tertiary centre.

RESULTS

A significant increase in urinary volume, urinary sodium excretion, mean arterial pressure, and decrease in plasma renin activity (p<0.05) was noted after 1 month of midodrine administration. There was also a significant decrease in cardiac output and an increase in systemic vascular resistance after midodrine therapy at 3 months (p<0.05). There was no change in glomerular filtration rate and model for end-stage liver disease (MELD) score. Midodrine plus standard medical therapy was significantly superior to standard medical therapy alone in the control of ascites (p=0.013) at 3 months. The mortality rate in the standard medical therapy group was significantly higher than the midodrine group (p<0.046). There was no significant difference in the frequency of various complications at the end of follow-up.

CONCLUSIONS

The results of this randomized pilot study suggest that midodrine plus standard medical therapy improves the systemic hemodynamics without any renal or hepatic dysfunction in these patients and is superior to standard medical therapy alone for the control of ascites.

Clinical manifestations of portal hypertension

The portal hypertension is responsible for many of the manifestations of liver cirrhosis. Some of these complications are the direct consequences of portal hypertension, such as gastrointestinal bleeding from ruptured gastroesophageal varices and from portal hypertensive gastropathy and colopathy, ascites and hepatorenal syndrome, and hypersplenism. In other complications, portal hypertension plays a key role, although it is not the only pathophysiological factor in their development. These include spontaneous bacterial peritonitis, hepatic encephalopathy, cirrhotic cardiomyopathy, hepatopulmonary syndrome, and portopulmonary hypertension.

Management of ascites in cirrhosis

Ascites is a common complication of liver cirrhosis associated with a poor prognosis. The treatment of ascites requires dietary sodium restriction and the judicious use of distal and loop diuretics, sequential at an earlier stage of ascites, and a combination at a later stage of ascites. The diagnosis of refractory ascites requires the demonstration of diuretic non-responsiveness, despite dietary sodium restriction, or the presence of diuretic-related complications. Patients with refractory ascites require second-line treatments of repeat large-volume paracentesis (LVP) or the insertion of a transjugular intrahepatic portosystemic shunt (TIPS), and assessment for liver transplantation. Careful patient selection is paramount for TIPS to be successful as a treatment for ascites. Patients not suitable for TIPS insertion should receive LVP. The use of albumin as a volume expander is recommended for LVP of >5-6 L to prevent the development of circulatory dysfunction, although the clinical significance of post-paracentesis circulatory dysfunction is still debated. Significant mortality is still being observed in cirrhotic patients with ascites and relatively preserved liver and renal function, as indicated by a lower Model for End-Stage Liver Disease (MELD) score. It is proposed that patients with lower MELD scores and ascites should receive additional points in calculating their priority for liver transplantation. Potential new treatment options for ascites include the use of various vasoconstrictors, vasopressin V(2) receptor antagonists, or the insertion of a peritoneo-vesical shunt, all of which could possibly improve the management of ascites.

Conivaptan: a step forward in the treatment of hyponatremia?

Hyponatremia is one of the most common electrolyte abnormalities linked to adverse outcomes and increased mortality in hospitalized patients. While the differential diagnosis for hyponatremia is diverse, most cases stem from arginine vasopressin (AVP) dysregulation, where hypoosmolality fails to suppress AVP synthesis and release. The physiological effects of AVP are currently known to depend on its interaction with any of 3 receptor subtypes V1A, V2, and V1B. Activation of V2 by AVP is the key in renal water regulation and maintenance of total body volume and plasma tonicity. Despite the long-recognized problem with excess AVP in euvolemic and hypervolemic hyponatremia, traditional therapeutic options have relied on nonspecific and potentially problematic strategies. More recently, a new class of drugs, introduced as “aquaretics,” has gained great attention among clinicians because of its ability to correct hyponatremia via direct competitive inhibition of AVP at V2 receptors to induce renal electrolyte-free water excretion. In this paper, we aim to review available clinical data on the only FDA-approved aquaretic, dual V1A/V2 receptor antagonist conivaptan, discuss its clinical indications, efficacy, safety profile, and comment on its clinical limitations.

Effects of a selective vasopressin V2 receptor antagonist, satavaptan, on ascites recurrence after paracentesis in patients with cirrhosis

BACKGROUND & AIMS

Cirrhotic patients with recurrent ascites frequently require paracentesis despite diuretic therapy. Vasopressin receptor antagonists, by increasing free water clearance, may reduce the recurrence of ascites. To investigate the effects of the addition of a vasopressin V(2) receptor antagonist, satavaptan, to 100mg spironolactone on ascites recurrence after a large volume paracentesis in patients with liver cirrhosis irrespective of the presence of hyponatraemia.

METHODS

One hundred and fifty one cirrhotic patients with recurrent ascites with or without hyponatraemia, and normal to mildly abnormal renal function were randomised in a double-blind study to receive either 5mg (n=39), 12.5mg (n=36), 25mg (n=40) of satavaptan or placebo (n=36) for 12 weeks. Their Child-Pugh scores were 9.2+/-1.3, 8.7+/-1.7, 8.8+/-1.3, and 9.0+/-1.5, respectively.

RESULTS

Median time to first paracentesis was 23, 26, and 17 days with satavaptan 5, 12.5, and 25mg, respectively, versus 14 days with placebo (ns for all doses). The frequency of paracenteses was decreased significantly (p<0.05) in all satavaptan groups versus placebo. Mean increase in ascites was 2.82+/-0.48 L/week for placebo versus 2.12+/-0.40, 2.14+/-0.33, and 2.06+/-0.40 L/week for the 5, 12.5, and 25mg of satavaptan, respectively (ns for all doses). Similar numbers of patients experienced major adverse events in all groups. Increases in serum creatinine, orthostatic changes in systolic pressure and thirst were more common with satavaptan.

CONCLUSIONS

Satavaptan has the potential to reduce recurrence of ascites after a large volume paracentesis at doses from 5 to 25mg in cirrhotic patients with ascites.

Hyponatremia increases mortality in pediatric patients listed for liver transplantation

To evaluate hyponatremia as an independent predictor of mortality in pediatric patients with end-stage liver disease listed for transplantation. We performed a single-center retrospective study of children listed for liver transplantation. We defined hyponatremia as a serum sodium concentration <130 mEq/L that persisted for at least seven days. The primary outcome was death on the waiting list. Ninety-four patients were eligible for the study. The prevalence of hyponatremia was 26%. Kaplan-Meier survival analysis demonstrated that patients with hyponatremia had decreased pretransplant survival compared with patients who maintained a serum sodium >130 mEq/L (p < 0.001). Univariable association analyses demonstrated death on the waiting list was also associated with higher median PELD scores at listing (p = 0.01), non-white race (p = 0.02), and age <1 yr (p = 0.001). Logistic regression analysis identified hyponatremia and non-white race as independently associated with pretransplant mortality [OR = 8.0 (95% CI: 1.4-45.7), p = 0.02 and OR = 6.3 (95% CI: 1.25-33.3), p = 0.03]. When hyponatremia was added to the PELD score, it was significantly better in predicting mortality than the PELD score alone (c-statistic = 0.79, p = 0.03). Hyponatremia identifies a subset of pediatric patients with increased risk of pretransplant mortality and improves the predictive ability of the current PELD score.

Ascites is a negative prognostic indicator in chronic hepatitis in dogs

BACKGROUND

Chronic hepatitis (CH) in dogs is common but little is known about factors associated with survival. Ascites is a well-recognized negative prognostic indicator in humans.

HYPOTHESIS

Ascites is a negative prognostic indicator in CH in dogs.

ANIMALS

Thirty-four dogs with histologically confirmed CH presented to 1 institution between 1996 and 2005.

METHODS

Retrospective observational study. CH was diagnosed by histopathology of liver tissue according to the WSAVA criteria. Ascites was diagnosed by abdominal ultrasound. The association of ascites with survival from diagnosis or onset of owner-reported clinical signs until death from any cause or from liver disease was analyzed. Ascitic and nonascitic groups were further analyzed for differences in treatment and sex.

RESULTS

Fourteen of 34 dogs had ascites. Survival from diagnosis to death from liver disease was 0.4 months (95% confidence interval [CI], 0.2-0.6) for ascitic dogs and 24.3 months (CI 11.4-37.1) for nonascitic dogs (P < .001), and from onset of signs to death from liver disease was 2.0 months (CI 0.0-5.6) for ascitic dogs and 33.0 months (CI 8.6-57.4) for nonascitic dogs (P= .0020). Diet and spironolactone use differed between groups.

CONCLUSIONS AND CLINICAL IMPORTANCE

Ascites is a significant negative prognostic indicator in dogs with CH. Veterinarians and owners can use this information to aid clinical decision making in affected dogs.

Review: Vasoconstrictors for the treatment of portal hypertension

Vasoconstrictors have long been used in an attempt to mitigate the effects of portal hypertension. In this review, we discuss the current understanding of portal hypertension and the use of vasoconstrictors in the management of its sequlae, including variceal hemorrhage, hepatorenal syndrome, and paracentesis-induced circulatory dysfunction. Experimental and clinical evidence for the use of vasoconstrictors is considered, and several exciting recent developments are reviewed.

Altered central TRPV4 expression and lipid raft association related to inappropriate vasopressin secretion in cirrhotic rats

Inappropriate vasopressin (AVP) release causes dilutional hyponatremia in many pathophysiological states such as cirrhosis. The central molecular mechanisms that mediate inappropriate AVP release are unknown. We tested the hypothesis that changes in the expression or trafficking of TRPV4 in the central nervous system may contribute to inappropriate AVP release in the bile duct ligation (BDL) model of cirrhosis in the rat. Four weeks after surgery, BDL rats demonstrated significantly increased plasma vasopressin and plasma renin activity (PRA), hypervolemia, and decreased plasma osmolality. These effects were blocked by providing BDL rats with 2% saline to drink for 15 days. TRPV4 protein expression was significantly increased in brain punches from BDL rats containing the supraoptic nucleus (SON) of the hypothalamus (100% +/- 11 to 157% +/- 4.8), and this effect was blocked in BDL rats given saline. Immunohistochemistry demonstrated a significant increase in TRPV4-positive cells and the percentage of AVP neurons that also were TRPV4-positive in the SON of BDL rats. In the hypothalamus of BDL rats, TRPV4 lipid raft association increased compared with sham (from 100% +/- 2.1 to 326.1% +/- 16). This effect was significantly attenuated in BDL rats given 2% saline to drink (174% +/- 11). In the brain stem, TRPV4 lipid raft association was reduced by BDL and inversely related to plasma AVP and PRA. We speculate that changes in TRPV4 expression and compartmentalization within lipid rafts could contribute to a feed-forward mechanism related to AVP release in cirrhosis.

Reabsorption of ascites and the factors that affect this process in cirrhosis

Ascites is one of the main features of liver decompensation in cirrhosis, and it is considered to be a dynamic process. In this study, we aimed to (1) measure the reabsorption rate of ascites; (2) evaluate whether these findings were related to features of ascites, hemodynamics, and serum measurements; and (3) examine morphologic changes in the diaphragm of cirrhotic patients. In all, 42 cirrhotic patients with ascites were enrolled in the study to comprise our study group. Using the dextran 70 test, patient ascites volumes and reabsorption rates were measured. Biopsies from the peritoneal side of the diaphragm were also processed for scanning electron microscopy and lymphatic immunohistochemical studies from the cirrhotic patients and control cadavers. The mean ascites reabsorption rate was 4.5 +/- 4.5 (0.18-14.6) mL/min, which correlated significantly with the calculated ascites volume (r = 0.75, P < 0.001). The mean ascites viscosity was 1.07 +/- 0.07 (0.99-1.17) centipoise, which demonstrated a high degree of negative correlation with the ascites reabsorption rate (r = -0.77, P < 0.001). Patients with a history of spontaneous bacterial peritonitis had significantly lesser ascites reabsorption rates than patients without this particular history. The size of lymphatic stomata in scanning electron microscopy depictions was increased, and lymphatic lacunae were dilated in immunohistochemical studies in the cirrhotic patients with ascites. However, these findings were not uniform in every cirrhotic patient with ascites. The volume and viscosity of ascites seem to influence its reabsorption rate. Additionally, previous episodes of spontaneous bacterial peritonitis may be responsible for the decreased ascites reabsorption rates observed in certain patient populations.

Clinical analysis of 21 cases with early misdiagnosis as hepatic encephalopathy

AIM: To investigate underlying causes for early misdiagnosis as hepatic encephalopathy and thereby to gain a better understanding of hepatic encephalopathy.

METHODS: Twenty-one cases misdiagnosed as hepatic encephalopathy were retrospectively analyzed, including their possible causes and clinical features.

RESULTS: Final diagnosis included hyponatraemia encephalopathy, alcohol withdrawal syndrome, chronic alcoholism Wernicke encephalopathy, hypoglycemic coma, cerebral hemorrhage and uremia acidosis. The underlying causes for misdiagnosis may be: narrow clinical diagnosis thinking; lack of complete understanding of pathogenic condition; undetailed inquiry and check-up and failure to master differential diagnosis of hepatic encephalopathy.

CONCLUSION: When patients with liver diseases present with mental disorders, detailed and complete inquiry and check-up are required, and relevant laboratory tests and causal analysis from perspective of diagnostic thinking should be done to avoid a misdiagnosis.

Cardiovascular dysfunction in patients with end-stage liver disease

Most patients with advanced liver disease have a normal or even supernormal ejection fraction judged by echocardiography. Thus, physicians previously assumed that cardiac function was normal in most patients with liver disease. However, further investigation has uncovered multiple problems in cardiac performance that place patients at risk of heart failure. Patients with liver disease have defects in both systolic and diastolic function that only become obvious with physiologic stress such as liver transplantation. In addition there are additional defects in the electromechanical coupling of the heart that can have significant clinical consequences. These collective pathologic changes are termed "cirrhotic cardiomyopathy" and occur to some degree in all patients with liver disease. This review will explore the pathophysiology of cardiovascular changes in patients with end-stage liver disease.

Renal phosphodiesterase 4B is activated in the Dahl salt-sensitive rat

Reduced beta-adrenoreceptor signaling is associated with increased sympathoadrenal activity in hypertensive patients and animal models of hypertension. However, the mechanism that accounts for this characteristic decline in beta-adrenergic signaling is unclear. In the present study, we investigated renal phosphodiesterase 4B, which metabolizes cAMP. Immunoblot analysis detected only the phosphodiesterase 4B4 isoform present in kidney tissue from spontaneously hypertensive rats, hypertensive Dahl salt-sensitive (SS) rats, and Dahl salt-resistant rats. The phosphorylated (activated) form of the protein was present at 2-fold greater levels in Dahl SS rats than in spontaneously hypertensive rats and Dahl salt-resistant rats, whereas the unphosphorylated form of the protein was reduced by approximately one half in SS animals. In accord with immunoblot data, rolipram-inhibitable cAMP hydrolyzing activity, a measure of PDE4 activity, was approximately 3-fold greater in kidney cytosolic extracts from SS rats than in extracts from spontaneously hypertensive rats and salt-resistant rats. Phosphodiesterase 4B expression was detected by immunohistochemistry in the renal vasculature, proximal tubules, and distal tubules. These results raise the possibility that increased PDE4 activity, specifically phosphodiesterase 4B4 activity, reduces beta-adrenergic signaling in the kidney and contributes to salt-sensitive hypertension in the Dahl SS rat.

Management of ascites and hepatic hydrothorax

The natural course of patients with cirrhosis is frequently complicated by the accumulation of fluid in the peritoneal or pleural cavities and interstitial tissue. Functional renal abnormalities that occur as a consequence of decreased effective arterial blood volume are responsible for fluid accumulation in the form of ascites and hepatic hydrothorax. Ascites is the most common complication of cirrhosis and poses an increased risk for infections, renal failure and mortality. Patients have a poor prognosis and it is estimated that nearly half will die in approximately 2 years without liver transplantation. Hepatic hydrothorax is defined as a pleural effusion greater than 500 mL (mostly right-sided) in patients with cirrhosis without cardiopulmonary disease; the estimated prevalence is approximately 5-10%. Liver transplantation is the most definitive cure for both conditions in those patients that are suitable candidates. However, the mainstay of therapy for minimizing fluid accumulation in both conditions includes sodium restriction and administration of diuretics. This article reviews the most current concepts of pathogenesis, clinical findings, diagnosis, and treatment of these complications of cirrhosis.

Acid-Base and Potassium Disorders in Liver Disease

Acid-base and potassium disorders occur frequently in the setting of liver disease. As the liver's metabolic function worsens, particularly in the setting of renal dysfunction, hemodynamic compromise, and hepatic encephalopathy, acid-base disorders ensue. The most common acid-base disorder is respiratory alkalosis. Metabolic acidosis alone or in combination with respiratory alkalosis also is common. Acid-base disorders in patients with liver disease are complex. The urine anion gap may help to distinguish between chronic respiratory alkalosis and hyperchloremic metabolic acidosis when a blood gas is not available. A negative urine anion gap helps to rule out chronic respiratory alkalosis. In this disorder a positive urine anion gap is expected owing to suppressed urinary acidification. Distal renal tubular acidosis occurs in autoimmune liver disease such as primary biliary cirrhosis, but often is a functional defect from impaired distal sodium delivery. Potassium disorders are often the result of the therapies used to treat advanced liver disease.

Impaired 11 beta-hydroxysteroid dehydrogenase contributes to renal sodium avidity in cirrhosis: hypothesis or fact?

Exaggerated renal sodium retention with concomitant potassium loss is a hallmark of cirrhosis and contributes to the accumulation of fluid as ascites, pleural effusion, or edema. This apparent mineralocorticoid effect is only partially explained by increased aldosterone concentrations. I present evidence supporting the hypothesis that cortisol confers mineralocorticoid action in cirrhosis. The underlying molecular pathology for this mineralocorticoid receptor (MR) activation by cortisol is a reduced activity of the 11 beta-hydroxysteroid dehydrogenase type 2, an enzyme protecting the MR from promiscuous activation by cortisol in healthy mammalians.

Vasopressin excess and hyponatremia

Hyponatremia is a common electrolyte disorder that frequently is overlooked and undertreated. Although the pathophysiological process of hyponatremia is complex, arginine vasopressin (AVP) is a common etiologic factor. Excess AVP release by osmotic or nonosmotic stimuli or both can lead to sodium and water imbalance. Conventional treatment options for hyponatremia, including water restriction and administration of sodium chloride with or without loop diuretics, do not directly address the underlying water retention induced by excess AVP in many cases. Clinical trials showed that AVP-receptor antagonists, including lixivaptan, tolvaptan, and conivaptan, produce aquaresis, the electrolyte-sparing excretion of free water, to correct serum sodium concentration. We review results from recent clinical trials involving AVP-receptor antagonists in the treatment of hyponatremia associated with AVP excess.

Review article: hepatic hydrothorax

Patients with cirrhosis and portal hypertension often have abnormal extracellular fluid volume regulation, resulting in accumulation of fluid as ascites, oedema or pleural effusion. These complications carry a poor prognosis with nearly half of the patients with ascites dying in the ensuing 2-3 years. In contrast to what happens in the abdominal cavity where large amounts of fluid (5-8 L) accumulate with the patient only experiencing only mild symptoms, in the thoracic cavity smaller amounts of fluid (1-2 L) cause severe symptoms such as shortness of breath, cough and hypoxaemia. Hepatic hydrothorax is defined as a pleural effusion, usually >500 mL, in patients with cirrhosis without cardiopulmonary disease. The pathophysiology involves the direct movement of ascitic fluid from the peritoneal cavity into the pleural space through diaphragmatic defects. The estimated prevalence among cirrhotic patients is 5-10%. The effusion, which is a transudate, most commonly occurs in the right hemithorax. The mainstay of therapy is similar to that of portal hypertensive ascites and includes sodium restriction and administration of diuretics. Refractory hydrothorax can be managed with transjugular intrahepatic portosystemic shunt in selected cases. Pleurodesis is not routinely recommended. Suitable patients with hepatic hydrothorax should be considered candidates for liver transplantation.